In the sport of golf, the impact between the golf club head and the golf ball controls the flight, height, and distance of the golf shot. Indeed, many skilled players are able to impart spin to the ball to curve the flight path of the ball once hit.
For example, a golf swing in which the golf club head from the inside of the golf ball towards the outside as the ball is struck imparts a counterclockwise spin to the ball as viewed from the top and for a right-hand golfer. This spin will cause the golf ball to travel in an arc in which the ball is drawn or moves left to right for a right-hand golfer. Conversely, a golf club swing in which the golf club moves from the outside and towards the inside of the golf ball as the golf ball is struck will impart an opposite spin to the golf ball. This opposite spin will cause the ball to move left to right or fade in the opposite direction from a draw. Still other variations of the golf swing will produce additional lift to the golf ball, cause the golf ball to travel in a lower projectile, etc.
Previously, there have been no known ways of easily and inexpensively determining the direction of the golf club head as the golf club head impacts upon the golf ball. Instead, it has been necessary, when practicing the golf swing, to estimate the direction of travel of the golf club head at impact from the results of the golf club shot, i.e. either a draw, a fade, or a straight shot.